This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Mercury (Hg) is a toxic environmental contaminant affecting human health, and exposure occurs mainly via dietary uptake of contaminated fish. To minimize exposure, state agencies issue advisories for the consumption of marine fish that are species-specific, but not geography-specific. The latter assumes that coastal fish contamination reflects large scale lifetime movement patterns rather than local Hg contamination. However, Hg contaminants in local fisheries may be predictable if causative factors are taken into account, e.g., spatial variation in Hg pollution from locally- and distantly-derived sources, dietary differences among fish species and across their various life stages, and residence time within water bodies of interest. Thus, research focusing on marine ecology and environmental chemistry is needed to support the development of models describing relationships between bioavailable Hg and local fish contamination. This investigation will focus on Narragansett Bay, RI, where local fisheries are important dietary and commercial resources for denizens of the state. RI land use and watershed characteristics, and potential point sources of Hg, will be correlated with measured values of Hg from site-specific collections of sediment and certain marine fish and invertebrate species. These data will be used within the framework of a geographic information system to create predictive models and analyze spatial relationships between RI land use and watershed characteristics, Hg pollution, and contamination in the marine food web. These empirical models will be evaluated and refined to include spatial and mechanistic factors underlying Hg bioaccumulation in marine fish, as determined by environmental Hg levels and food web analyses. Finally, models predicting Hg levels in commercially and recreationally important finfish will be tested against measured Hg levels in locally-consumed fish, provided by anglers and local commercial fish markets. The outcome of this research will be improved accuracy in the assessment of the risks to human health of marine fish consumption.